There have been several studies concerning the neural basis of walking. One of the more fully studied systems is cockroach walking because: 1) patterns of innervation are established; 2) morphological and physiological properties of some muscles have been described; 3) evidence exists for an interneuronal central pattern generator, and 4) specific motor neurons and interneurons have been identifed. There are a few studies on afferent input; such studies are difficult to interpret since the technique used, ablation and holding the limb rigid while manipulating the sense organ, can influence other receptors. This proposal presents an experimental technique whereby the main sensory leg nerve on one side of the body (right) is crossed to the opposite side (left) and regenerates. The motor axons regenerate via the crossed-nerve and innervate their contralaterally homologous muscles. The left sensory axons regenerate via the crossed-nerve and enter the right side of the CNS. Afferent innervation can be specific since a monosynaptic reflex is formed between left side afferents and right side afferents. This discovery has permitted a new approach for studying sensory influence on motor output. Cross-innervated legs can be de-efferented leaving an afferent limb. The specific aim is to study the role specific sense organs may play in walking.